Change mobifyjs-utils dependancy to download with git:// link

Status: **Opened for visibility**

Reviewers: ** @MikeKlemarewski @kbingman **
Linked PRs: ** https://github.com/mobify/generator-adaptivejs/pull/68 **

## Changes
- Changes mobifyjs-utils dep to use git:// url

## How to test-drive this PR
- Have git setup so that it doesn't know how to authenticate to github via ssh keys
- bower install
- Did things install properly?